07harleyD

I'm having a problem with my truck running to lean which means she is starving for fuel, which is causing detonation and I also have a misfire on cyl#5. This has been going on for a 6 or 7 months now, had it into the dealer 3 times and $2500.00 in parts and labour later, I'm still no further ahead. It only happens in the higher RPM's, when I'm going up a long steep hill or if I'm on the highway and pull out to pass a vehicle, it stumbles very bad and throws the misfire code P0305 which is cyl#5, just driving around the city she is perfect. Yesterday while driving up a hill it started misfireing and I barley made it up, it gave me two codes, P0305 and a P1285 which is cylinder head over temp, and goes into failsafe mode but doesn't actually go into failsafe mode, it pops up for a second and my temp gauge pins on hot and then everything goes back to normal, once I'm on the level again. Then on the way back I got the P0305 again and then it gave me a P0402 which is my catalytic converter bank 1. for the people who don't know it's an 07 F150 with a Whipple supercharger kit. I Don't know what to do next?? The truck has:

-new plugs
-new coils
-new fuel filter
-new injector
-fuel pump is good
-dealer tells me there are no vaccum leaks
-new fuel pump module
-all exhaust leaks were fixed (had a cracked manifold)
-cleaned MAF sensor
-compression is good

Ian_T_S

Going up hill and getting cyl. over temp...I would look into the oil system. Pump, filter, maybe build up in a line/port/cavity etc...or I may be way off but thought I'd throw in my 2cents worth

07harleyD

Oil pressure is good, and I always change my oil every 5000kms faithfully.

Pcwiz13

Your not using FRAM filters are you? I've understand that is a big NO NO in these motors, the filters tend to come apart and can clog up oil passages.

Over temp on a hill makes me think oil also.

Mod (Ret.)

I like your avitar!

Pcwiz13

Thanks! It seemed fitting at times around here, lol

Sent from my iPhone

07harleyD

I Always use factory filters. The truck doesn't run hot, it's always in the normal range but when this failsafe message pops up it pins on hot but only last for about 30 second or so then everything goes back to normal.

Ian_T_S

I wonder if one or some of your valves are sticking intermittently, I know you said compression is good but with the exhaust leak, depending on how bad it was, you may have burnt a valve or warped one

07harleyD

I hope not, I'm gonna have to make another trip to the dealer and get my O2 sensors checked alond with my cats, but I don't think that was my problem in the first place. The misfire and detonation problem I'm having caused one of my cats to plug I think, now I'm getting a P0420 and I never got that before, just the P1285, and the P0305. I'm getting tired of throwing parts at it with no result. I want to drop it off at the dealer and tell them to keep it until it's fixed but I know it will be an arm and a leg when it's done.

Ian_T_S

Why are you going to the dealer? I did and wasted an extra 2k just paying their prices. I found a guy that works at Mytee and is an expert and they cut dealer prices in more than half and used Ford parts...no aftermarket Chinese crap.

Good thought with the cats, do you have an exhaust system on there now?